As I think was mentioned a couple of days ago, it's not an easy thing
to create a port of Rockbox for a particular player. Someone, or a
group, has to reverse-engineer the player and figure out how to make
Rockbox work on it. They have to buy the player and figure it out on
their own time with no compensation. So unless a Rockbox developer
has a Zune, wants to make it work, has the time, and can figure it
out, no port will be created.